9.7 Signing and Encrypting Messages

MH-E can sign and encrypt messages as defined in
RFC 3156. If you
should choose to sign or encrypt your message, use one of the
following commands to do so any time before sending your message.

The command C-c C-m C-s (mh-mml-secure-message-sign)
inserts the following tag:

<#secure method=pgpmime mode=sign>

This is used to sign your message digitally. Likewise, the command
C-c C-m C-e (mh-mml-secure-message-encrypt) inserts the
following tag:

<#secure method=pgpmime mode=encrypt>

This is used to encrypt your message. Finally, the command C-c
C-m s e (mh-mml-secure-message-signencrypt) inserts the
following tag:

<#secure method=pgpmime mode=signencrypt>

This is used to sign and encrypt your message. In each of these cases,
a proper multipart message is created for you when you send the
message. Use the command C-c C-m C-n
(mh-mml-unsecure-message) to remove these tags. Use a prefix
argument (as in C-u C-c C-m s e) to be prompted for one of the
possible security methods (see mh-mml-method-default).

The option mh-mml-method-default is used to select between a
variety of mail security mechanisms. The default is ‘PGP (MIME)’
if it is supported; otherwise, the default is ‘None’. Other
mechanisms include vanilla ‘PGP’ and ‘S/MIME’.

The ‘pgg’ customization group may have some settings which may
interest you.
See
The PGG Manual.

In particular, I turn on the option pgg-encrypt-for-me so that
all messages I encrypt are encrypted with my public key as well. If
you keep a copy of all of your outgoing mail with a ‘Fcc:’ header
field, this setting is vital so that you can read the mail you write!